Math Problem Statement
Questions 1 to 22 carry 3 marks each.
7 A contractor hired a group of workers to do a job in 3 days. But due to poor work conditions, 8 workers dropped out every day, and hence the job could be completed only at the end of the 5th day. Initially how many workers were hired by the contractor?
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45
-
40
-
48
-
36
Solution
Let the initial number of workers hired by the contractor be .
The job was supposed to be completed in 3 days. Therefore, the total work is equivalent to worker-days (i.e., the total amount of work that needs to be done is workers working for 3 days).
However, because 8 workers dropped out each day, the job was completed in 5 days instead. Let's calculate the number of workers available each day:
- On Day 1, there are workers.
- On Day 2, 8 workers dropped out, so there are workers.
- On Day 3, 8 more workers dropped out, so there are workers.
- On Day 4, 8 more workers dropped out, so there are workers.
- On Day 5, 8 more workers dropped out, so there are workers.
The total work done over the 5 days can be calculated as the sum of the number of workers each day:
Simplifying this expression:
Since the total amount of work is the same, we equate this to the original work, :
Solving for :
Thus, the initial number of workers hired by the contractor is .
Would you like more details or have any questions?
Here are some related questions for practice:
- If 10 workers dropped out every day, how many workers were initially hired?
- What if the job was supposed to be done in 4 days but took 6 days instead?
- If the job took 7 days due to 5 workers dropping out daily, how many were initially hired?
- How does increasing the daily dropout rate affect the total number of days?
- Can you express the total work in terms of , where is the number of days the job took?
Tip: Breaking down word problems into smaller steps helps simplify the solution.
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Math Problem Analysis
Mathematical Concepts
Algebra
Linear Equations
Word Problems
Formulas
Total work = number of workers * number of days
Summation of workers available each day: x + (x - 8) + (x - 16) + (x - 24) + (x - 32)
Theorems
Basic principles of work and time (Work = Workers × Time)
Suitable Grade Level
Grades 9-11
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